Regret is information arriving after the deadline. The discomfort is your own standard registering a gap between what you did and what you actually think is right, which means the regret is proof the standard exists. Useful for about ten minutes. After that it stops telling you anything new and starts just running.

Give the next one a short hearing: name the value it points to, and name one thing you would do differently. Then do that thing somewhere it still applies, which is usually with the same people. Carrying it past that point helps nobody.